Kapt3: Write stub class files with metadata (needed for incremental compilation)

compiler/testData/codegen/light-analysis/classes/classObjectField.txt

@@ -1,3 +1,4 @@
+@kotlin.Metadata
 public final class A {
     public final static field Companion: A.Companion
     private final static field value: int
@@ -5,12 +6,14 @@ public final class A {
     public method <init>(): void
 }
 
+@kotlin.Metadata
 public final static class A/Companion {
     inner class A/Companion
     private method <init>(): void
     public final method getValue(): int
 }
 
+@kotlin.Metadata
 public final class ClassObjectFieldKt {
     public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
 }